Forum Moderators: buckworks
If you decide to go for a merchant account, some gateways will offer a relatively simple HTML integration and customizable hosted checkout pages. You would need both a gateway and an internet merchant account in that case, and both of those will likely have some startup and/or monthly fees.
Does your site currently tell customers that they can pay with a credit card in your PayPal checkout? If all they see is "PayPal payments" they might assume they are required to open a PayPal account. If you're just processing individual payments (not subscriptions) you should be able to offer them Account Optional* checkout where they can pay by credit card without creating a PayPal account. Letting them know about the Account Optional checkout while they are still on your website should help reduce confusion once they get to the PayPal site.
*Account Optional checkout is currently not available for merchants in Germany.
EDIT: My apologies - didn't notice that the second reply was also from you. PayPal doesn't offer an "Account Optional" version of its subscriptions, and Website Payments Pro will probably not quit your needs either, since you would not be permitted to store the customer's card verification number (and therefore would not be able to bill the customer regularly without them re-entering that info).
If you are researching online payment gateways, most will have some "Recurring Billing" feature.